Image Pickup Apparatus Pixel Read-Out Control for Focus Detection
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Solution Overview
Problem
Image pickup apparatuses with multiple photodiodes require a long time to read out signals from all pixels, leading to increased read-out time and exposure amount differences during focus detection and image generation, especially in slit rolling operations.
Innovation Solution
The apparatus independently reads out signals from each photodiode in pixels used for focus detection while adding signals from photodiodes in other pixels for image generation, ensuring consistent read-out times across pixel rows to minimize exposure differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If each pixel includes multiple photodiodes for focus detection and image generation, then focus detection capability is improved, but read-out time increases
Solution Approach 1:
The pixel array is divided into two distinct regions: a first pixel region where signals from multiple photodiodes are read out independently for focus detection, and a second pixel region where signals are added together for image generation. This segmentation allows simultaneous optimization of both focus detection capability and read-out efficiency by processing different regions with different strategies.
2Measurement precision
If signals from all photodiodes are read out independently, then focus detection precision is improved, but read-out time increases significantly
Solution Approach 1:
Different read-out strategies are applied to different spatial regions of the pixel array. The first pixel region uses independent signal read-out for high-precision focus detection, while the second pixel region uses signal addition for efficient image generation. This local quality approach ensures that precision is optimized where needed without compromising overall productivity.
3Productivity
If read-out time for focus detection is reduced, then productivity is improved, but exposure amount differences between pixel rows increase
Solution Approach 1:
The pixel array is pre-configured with two distinct regions designed for different functions. The first pixel region is dedicated to focus detection with independent read-out, while the second pixel region is dedicated to image generation with signal addition. This preliminary arrangement allows the system to maintain consistent exposure times across all pixel rows while enabling fast read-out for focus detection without compromising image quality.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for satisfactory image quality with reduced read-out time and minimized exposure amount differences, maintaining consistent accumulation times during slit rolling operations.
Implementation Method 1
an image pickup element (106) including a plurality of pixels (200), each pixel (200) including a plurality of photodiodes (601a, 601b)
Data Source
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AI summary
An image pickup apparatus including an image pickup unit configured to employ a first mode and a second mode; and a controller configured to read out, in the first mode, a first row, and read out, in the second mode and a mode different from the second mode, a second row, the first row being read out in the first mode during a first read-out period, the second row being read out in the second mode during a second read-out period, the second row read out in the mode different from the second mode during a third read-out period, and the first to third read-out periods having the same length.